Most printing technologies available today have been developed for the purpose of placing an image on a substrate, such as paper and plastic films, having a reasonable degree of permanence. Some of the typical technologies, which are all highly developed, include lithography, gravure, offset, toner fusion, flexographic, and inkjet. Toner fusion and inkjet technologies permit real-time continuously variable imaging.
The foregoing printing technologies have generally not been developed for mask printing applications. Mask printing applications include printed images that are durable enough to withstand exposure to various solvents, washes, and manufacturing processes. Mask printing applications are designed to be removed readily when the printed mask is no longer required. Currently, mask printing applications are used when creating tamper-evident labels.
For mask printing on metallic substrates, which are later intended to be anodized, water-based flexographic inks have been used with good success. Water-based flexographic inks remain in place during anodization steps and can be easily removed later in a water bath. In contrast, water-based ink jet inks and print-delivery systems (ink-jet heads) print poorly on metallic substrates and do not have the right combination of adhesion and removability to work as a printed mask when anodization steps are used. Conversely, images printed with ultraviolet cured inkjet inks show very high image definition and quality, but are much more difficult to remove with most commonly used industrial processes. As such, under most circumstances, UV cured inkjet inks do not have the right combination of adhesion and removability to work as a printed mask when anodization is used.
Therefore, there is a need for a method of implementing UV cured inks that produces a proper combination of adhesion and removability during anodization steps of mask printing and tamper-evident label creation.